Rust inhibiting coating compositions



Patented June 7, 1949 UNITED STATES PATENT omen RUST INHIBITING COATING COMPOSITIONS 'Loy S. Engle, Harrington Park, N. J., and Walter Fikar, Jackson Heights, N. Y., assignors to Intercliemical Corporation, New York, N. Y., a

corporation of Ohio No Drawing. Application May 13, 1944, Serial No. 535,558

3 Claims. This invention relates to temporary rust-inhibitive coatings of the class known to the trade as slushing oils, and aims to provide a surface U; S. Patent No. 2,080,299, issued May 11, 1937.

These rust-inhibiting slushing oils have presented a serious disadvantage,in use, due to the factthat uniform thin films of the oil are difficult to obtain. Because substantial quantities of oil must be applied, the metal must be degreased before the permanent paint film is applied. Furthermore, the unevenness of the applied film causes rusting in the thin spots. a

We have discovered a new type of slushing oil, characterized by the fact that it produces rustinhibitive thin uniform films which can be finished without degreasing. Our slushing oils are very largely (70% or more) volatile solvents, having dispersed therein heat-bodied unsaturated glyceride oils and containing a small percentage of alkyl phosphate as a rust-inhibiting agent.

We may use any heat-bodied unsaturated glyceride oil for our purpose, whether drying, semidrying or non-drying, since all of the heat-bodied oils possess the property of readily wetting metal. However, we get our best results with the nondrying fractions obtained in the solvent fractionation of heat-bodied drying oils such as linseed, fish, perilla, poppy seed and soya oils, as described in the Eibners U. S. Patent No. 1,870,- 103. Such non-drying fractions, when applied as thin solutions in mineral spirits or other solvent, give a substantial measure of protection to metal without any rust-inhibitor, whereas ordinary mineral and glyceride oils give little protection without the inhibitor.

Our new slushing oils are characterized by their extremely good wetting of metal. Thus, on dipping, roller coating; or similar application, they spread evenly over the metal; on evaporation of a solvent, an extremely thin film remains. This film dries very slowly, as the alkyl phosphate is an antioxidant; it therefore remains permanently adhesive, so that it stays bonded to the metal On coating with a permanent finish, the oil is absorbed by the vehicle of the finish. Drying oil resinous, oleoresinous and lacquer finishes are all compatible with the residue.

Preferably, we use a minor percentage (from 1 to 10%) of a volatile water-immiscible aliphatic alcohol (butyl to hexyl alcohols) in the composition; due to improved dispersion, they produce improved smoothness of film which is highly useful where the film is to be coated over without removal.

Preferably, we heat the bodied glyceride oil to about 150 C. with an acid alkyl phosphate. A

' reaction of obscure nature occurs at about this point, resulting in more permanent dispersionof the phosphate in the oil. This reaction of phos- This composition can be coated to a non-drying film, which will withstand well over 650 hours (extent of test) in humidity at F. without signs of rusting. Its principal weakness is a tendency to separate on standing, so that coating is difficult. a

The composition without the phosphate fails in the test after 54 hours; the bare steel fails in 6 hours. Comparatively, a half-dozen mineral oils, and refined linseed oils, fail in 6 hours; bodied unfractionated linseed oils fail in 22 hours.

Example 2 When the oil of Example 1 is heated to C. with the phosphate, reaction occurs. The product made with the percentages of Example 1 shows better dispersion, and is far more stable than Example 1. Rust-inhibition is at least as good.

Ea'ample 3 If the products of Examples 1 and 2 are reformulated by replacing 5% of the mineral spirits with n-amyl alcohol, an even smoothermixture is obtained.

The addition of aliphatic'amines to the compositions helps somewhat in insuring compati- 3 bility. A typical formula utilizing an amine is the following:

As pointed out above, the reaction product of an acid alkyl phosphate and a heat-bodied vegetable drying oil is useful in mineral oil compositions where dispersion of the phosphate is a probiem-thus:

Example Parts by weight Mono amyl ortho acid phosphate 5 0 Bodied linseed oil are heated together at 150- 0., and added SAE 20 Penn. lubricating oil 80.0 Mahogany sulionates (oil soluble petroleum v SLIHODMGS) 5.0

In general, we can use as the rust-inhibiting agents the various alkyl phosphates, whether acid or neutral esters. The amount used may vary from a small fraction of a percent, up to a substantial figure; for best results, we prefer to use from about /2 to As indicated above, the heat-bodied oils used may be any of the glyceride oils, although optimum results are obtained with the non-drying fractions of heat-bodied drying oils. This 011 should not exceed about 30% of the composition, but should be at least about equal in weight to the aliwl phosphate. The proportions shown in the examples can be widely varied, but where it is desired to coat over the rust-inhibiting composition film without removal of the composition, the composition should contain at least 70% volatile solvent.

We claim:

1. A rust-inhibiting composition, character- '4 ized by the ability of its films to be coated without being removed, consisting essentially from about to 10% by weight of alkyl phosphate, a heat-bodied oil in at least approximately as great quantity as the phosphate, but not exceedin about 30%, and 70% or more of volatile solvent.

2. A rust-inhibiting composition, characterized by the ability of its films to be coated without being removed, consisting essentially from about /2 to 10% by weight 01 alkyl phosphate, a heatbodied oil in at least approximately as great quantity as the phosphate, but not exceeding about v 30%, and 70% or more of volatile solvent, includsolvent.

ing a minor percentage of a water-immiscible aliphatic alcohol.

3. A rust-inhibiting composition, consisting essentially the reaction product obtained by heating together, to about 150 C., a heat-bodied glyceride oil and an acid alkyl phosphate, dissolved in a volatile solvent, there being present from about to 10% by-weight of alkyl phosphate, heat-bodied glyceride oil in at least approximately as great quantity as the phosphate, but not exceeding about 30%, and or more of volatile LoY s. ENGLE.

WALTER. FIKAR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STA'I'ES PATENTS Number Prutton Nov. 25, 1938 Balassa Oct. 28, 1941 Non Dijck Sept. 1, 1942 Caplan Dec. 3, 1940 H Certificate of Correction Patent N0. 2,472,099: June 7, 1949.

LOY S. ENGLE ET AL.

It is hereby certified that error appears-1m the printed specification of the above numbered patent requiring correction as fqlldws:

Column 4, line 35, list of references cited, for the patent number 1,529,102 read 1,592,102;

THOMAS F. MURPHY, 

